If you understand what these scales are made of (which is actually quite simple) and also how chords are constructed (which is equally simple), it will be obvious which scale fits with which chord – no memorizing will be necessary beyond that.

It’s similar with learning scales. If you understand how scales are constructed, in other words what one scale contains compared to another scale, learning them will be much easier. In understanding them this way, you’ll see that it’s not really a matter of memorizing lots of scales but more like choosing a palette of colours to paint a picture.

Learning the fingering shapes for scales is something you will have to do and this does take some practice. Learning scale shapes, like learning chord shapes, is to a large extent about practising them until they become part of “muscle memory”. In other words, your fingers just know them without you having to think about it.

However, it is important when doing this practice, that you at the same time learn what these scales contain – so that by the time your fingers know the shapes, they also know what the scales contain – without thinking about it. I’ll explain what I mean about this below.

You want to minimise thinking (eliminate it if possible) when you play. This means building in everything you need to the point where you don’t need to think about it. Getting to this stage is just a matter of the right sort of practice.

Knowing what different scales contain is important. It makes it much easier to learn them and use them. What do I mean when I talk about what a scale “contains”?

Each scale contains a set of notes, one of which is the root note. Think of the root note as your home point in the scale. Also, very importantly, realise that the root note of the scale is always the same as the root note of the chord you are playing over at the time. I can’t emphasise enough how important this last point is.

Every other note in the scale is some distance from the root note. This distance defines the sounds of each of the notes in the scale. These “distances” are called intervals.

Each interval has its own sound, and learning these sounds is probably the most important thing any player who wishes to improvise can do.

Knowing how these intervals sound when played over major, minor and dominant 7th chords, gives you the tools you need to use scales effectively. When you know these sounds, it becomes patently obvious which scale to use for which chord. It will become crystal clear, because you’ll know how each interval in the scale will sound over the chord, so it becomes very easy to choose the scale with the intervals you want to hear.

This assumes, of course that your fingers have learned the shapes, and you’ve learned where the intervals are in the shapes – which as I said earlier is very important to do as you practice the shapes.

Using the methods and tools outlined above, you can learn scales in a quick and efficient way, and you’ll know how to use them.